What's their major and job title?
I think they're awesome and created a good look and feel with the use of only a few images.
Jeremy Kratz is the primary designer of Stack Overflow. Don't know what he majored in (you'd have to ask him) but he is a professional designer.
Call me a bonehead but I found the UI a bit confusing at first:
I've since gotten used to the UI though, and find it simple, easy to use and very utilitarian.